diff --git a/attachment_s3/models/ir_attachment.py b/attachment_s3/models/ir_attachment.py
index e0bb796..ef5f379 100644
--- a/attachment_s3/models/ir_attachment.py
+++ b/attachment_s3/models/ir_attachment.py
@@ -122,6 +122,8 @@ class IrAttachment(models.Model):
                 bucket.meta.client.head_object(
                     Bucket=bucket.name,  Key=key
                 )
+                if bin_size:
+                    return bucket.Object(key).content_length
                 res = io.BytesIO()
                 bucket.download_fileobj(key, res)
                 res.seek(0)